Method for determining the sensitivity and/or specificity of an assay system for detecting antibodies

ABSTRACT

A method for determining the sensitivity and/or specificity of assays that detect the presence or absence of antibodies to viral and/or other microbial infective agents using porcine seroconversion panels, and production of the seroconversion panels is provided.

This is a continuation of U.S. application Ser. No. 07/611,307, filedNov. 9, 1990, which is incorporated herein by reference, which is acontinuation-in-part of U.S. application Ser. No. 07/192,241, filed May10, 1988 (issued as U.S. Pat. No. 5,008,183 on Apr. 16, 1991), which isincorporated by reference.

TECHNICAL FIELD

The present invention relates to the use of porcine seroconversionpanels for determining the sensitivity and/or specificity of assaysystems for detecting the presence or absence of antibodies to viraland/or other microbial infective agents, and to a method of producingthe porcine seroconversion panels. In particular, the invention pertainsto the use of porcine immune IgG, porcine immune IgA, and porcine immuneIgM seroconversion panels.

BACKGROUND OF THE INVENTION

Assay systems capable of detecting the presence or absence of antibodiesgenerated in response to the presence of antigens are well known. Suchassay systems have proved useful in, inter alia, the diagnosis ofvarious diseases. For example, viral infections, such as AIDS (acquiredimmune deficiency syndrome) and CMV (cytomegalovirus) may be diagnosedwith assays which detect the presence of viral antibodies includingimmunoglobulins IgG, IgA, and IgM, in patients suspected of having thesediseases. Examples of such assay systems which employ antigen-antibodybinding include ELISA, Western Blot, Quick Western Blots (U.S. Pat. Nos.4,816,387 and 4,855,235) and RIA. Such diagnostics uniformly includecontrols to insure the integrity of the test system.

Typically, the diagnostics have both positive and negative controls. Thepositive control provides pertinent information concerning the activityof the test system, i.e., that reactive antibodies specific to theantigens used in an antibody test system are bound to the antigens(indicating that the antigens used in the test system are workingproperly), and that the anti-immunoglobulin used to detect the boundimmunoglobulin is working. In the case of an ELISA system theanti-immunoglobulin may be labeled with an enzyme (conjugate) whichactivates a substrate added to the system to give a chromogen reaction;in this case the positive control indicates whether the conjugate hasreacted, and whether the substrate has worked properly as an activatedchromogen. A negative control provides information about the absence ofreactive antibodies specific to the particular antigens used in a testsystem. It also provides information as to the reaction level,determined by the signal used in a particular test, at which a specimenmay be considered negative.

The cut-off point in a particular test is often based upon the relativevalue obtained by a positive control and/or by the negative control. Anacceptable detection range obtained by the controls utilized with aparticular type of test kit is specifically designed and titrated forthat type of kit. The positive control "value" obtained in a particulartest system affects the sensitivity of that test system; the negativecontrol "value" affects the specificity of the test system.

Seroconversion panels are conventionally used to estimate thesensitivity and specificity of diagnostic tests or assay systems. Aseroconversion panel is made by drawing consecutive blood samples overtime from a donor infected with a known microbial organism. The day thatthe blood sample is taken is the time point for that sample. The bloodserum contains antibodies to the microorganism such as IgG, IgA, andIgM. Seroconversion panels containing antibodies to retroviruses such asHIV-1, HIV-2, HTLV-1, and HTLV-II, and to other microorganisms such astoxoplasma, cytomegalovirus, Borellia b. (LYME), and Rubella, have beenobtained by following certain plasmaphoresis donors or by repeatedlydrawing blood samples from high risk individuals. The collected bloodfrom each drawing is then tested for the presence of antibodies to themicrobial organism and aliquotted in minute volumes, typically 100 to250 microliters (ul) and stored for future use. The consecutive timepoint samples as a group constitute a seroconversion panel.

Notably, the supply of antibodies is scarce and uncertain and thequality and characteristics of the antibody varies from donor to donor.Further, as more successful therapies become known and used, fewerseropositive donors will be available, and thus the required antibodyeven more difficult to obtain.

In the case of AIDS patients it has been found that the condition ofpatients who donate blood or are subjected to plasmaphoresisdeteriorates rapidly. Therefore, obtaining AIDS Positive blood or plasmafrom patients as a source of antibody for use in a seroconversion panelshould be avoided.

The previously mentioned assay systems detect infection indirectly bydetection of the presence or absence of antibodies. Seroconversionpanels disclose how early an infection can be detected.

These assay systems detect the presence or absence of IgG(immunoglobulin G). Such assays only allow "controlled" detection(measurement defined by use of anti-IgG conjugate and of antibodypositive control) of the presence of IgG in blood and body fluidsdirected to antigens used in the test systems. The appearance ofdetectable IgG directed to antigens in an infected/immunized individualdoes not occur until 30-40 days after initial infection in manyinstances. The IgG class antibodies are often present for months oryears after infection/immunization.

The presence of circulating IgG directed to immunizing antigens duringthe course of an infection (or after immunization) is preceded by thepresence of circulating IgM and/or IgA antibodies directed towards theantigens/immunogens. IgM and/or IgA antibodies directed to antigens inan infected/immunized individual are often present in detectablequantities as early as 14 days (or earlier) after theinfection/immunization. The IgM class antibodies gradually lose titer30-35 days after initial infection/immunization.

It is widely recognized that diagnostics which can detect antibodiesother than IgG are desirable. For example, it is known that generallyafter confrontation with a foreign body, the human immune systemresponds by generating antibodies against the foreign body or antigen.It is believed that IgM and/or IgA, not IgG is produced first. As can beappreciated, assays capable of detecting IgM and/or IgA will facilitateearly detection of numerous diseases. IgM is, however, a relativelyshort-lived antibody. While it may be produced shortly after infection,IgM levels fall, eventually below detectable levels, as IgG is producedin increasing amounts. Because IgM has a short life span, IgM levels aretypically below detectable levels before many diseases are evendiagnosed. Therefore, IgM is not readily obtainable from seropositivedonors and a dependable, reliable source of this important antibody isneeded.

Seroconversion panels can be used to test each manufactured batch ofassay systems or diagnostic test kits to ensure that the assay systemperforms with the same high sensitivity and specificity each time it isto be released for distribution. Test laboratories which use such assaysystems or test kits can use seroconversion panels to ensure that thelaboratories are performing high quality testing.

The present invention overcomes the previously mentioned disadvantagesbecause it provides the ability to produce the desired seroconversionpanels, i.e., porcine IgG, IgA, and IgM antibody seroconversion panels.In accordance with the present invention, there is provided a method ofusing the porcine seroconversion panels to determine the sensitivityand/or specificity of assay systems detecting antibodies to viral and/ormicrobial infective agents.

SUMMARY OF THE INVENTION

The present invention provides a use of porcine seroconversion panelsfor determining the sensitivity and/or specificity of assays that detectthe presence or absence of antibodies which bind to viral and/or othermicrobial antigens and production of porcine seroconversion panels. Inparticular, the invention is useful in connection with assays in whichpredetermined antigens are sequentially contacted with a biologicalfluid and positive control comprising antibodies to the antigens fortimes and under conditions sufficient for the antigens and anyantibodies in the biological fluid, and the antigens and antibodies inthe positive control, to form antigen-antibody complexes, and theformation of the complexes is therewith detected. The sensitivity and/orspecificity of the assay is determined by using seroconversion panelscontaining human antibodies to the antigens instead of the biologicalfluid, the improvement comprising the use of seroconversion panelscontaining porcine antibodies which bind to the antigens and react toanti-human antibody.

The present invention can be used to provide seroconversion panelscontaining known titers of antibodies to predetermined antigens. Thesensitivity and/or specificity of different assays for detectingantibodies to the predetermined antigens can be compared by using eachassay to measure the presence of the antibodies in the seroconversionpanels and comparing the measurements. The comparison of themeasurements obtained by the different assays will show which assay ismore sensitive and/or more specific.

It is presently preferred to use porcine immune IgG, IgM, and/or IgAseroconversion panels.

A further advantage of the present invention is that porcineseroconversion panels can be produced with antibodies reactive topredetermined antigens of only one viral or other microbial infectiveagent or of a plurality of viral or other microbial infective agents. Nosuch manipulation is possible with human donor derived seroconversionpanels.

A further advantage of the present invention is that a porcineseroconversion panel containing a plurality of antibodies to a group ofmicroorganisms, such as human retroviruses HIV-1, HTLV 1, HIV-2 andHTLV-II can be used by makers of assay systems to develop and controlthe sensitivity and specificity of their assay systems to detect any oneof the plurality of antibodies in the same assay. Such an assay wouldenable one test to be performed on a sample instead of a series ofindividual assays to detect one antibody at a time. If a positivereaction is obtained, then the sample can be tested further, ifnecessary, to determine the exact antibody that is reacting. Forexample, blood banks which screen donated blood for the presence of AIDSantibodies, could use an assay containing antigens to HIV-1, HTLV-1,HTLV-II and HIV-2, instead of four individual assays using only oneantigen. If the test sample is not reactive, then no further testing isrequired. If the test sample is reactive, then the sample could befurther tested, if necessary, in assays using one of the four antigensto identify the viral antigen to which the test sample is reacting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents the results of a Western Blot assay measuring thepresence of HTLV-1 IgG in a porcine seroconversion panel and thecorresponding results of the ELISA assay on the same panel. Samples arenumbered 1 to 15, the negative control is identified as "NC", and thepositive control is identified as "PC". The time point is listed belowthe sample. The ELISA optical density (O.D.) reading of the sample ispresented below the time point. The Western Blot result for a sample isshown above the sample number with protein identifying band numbers 15,19, 24, 26, 28, 32, 36 and 53 and glycoprotein identifying band number46 presented in numerical order to the right of the PC sample. The bandnumbers are used to identify the band in the sample that aligns with thecorresponding band number in the right hand column.

FIG. 2 presents the results of a Western Blot assay measuring thepresence of HTLV-1 IgM in a seroconversion panel and the correspondingresults of the ELISA assay on the same panel illustrated in the samemanner as FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, porcine seroconversion panelsare obtained by immunizing a pig with viral or other microbial materialagainst which it is desired to raise specific antibodies and drawingsequential time point samples of antibody-containing blood from theimmunized pig, with aliquots of these time point samples being used tomake seroconversion panels. Examples of suitable immunizing agentsinclude HIV-1, HIV-2, HTLV-1, HTLV-II, CMV, LYME, toxoplasma, Rubella,and Epstein-Barr virus. Of course, other immunizing agents as may beknown to those skilled in the art are also useful.

The immunization begins with a first vaccination of the animal with apreparation comprising 10-500 micrograms (ug) of viral or microbiallysate or selected portions of the viral core or envelope proteins or ofthe microbial core or membrane Proteins. Viral material is generallysolubized in Triton X-100; SDS, (sodium dodecyl sulfate),mercaptoethanol, and/or NP 40 (Nonidet P40 detergent, nonionicdetergent), and suspended in phosphate buffered saline (PBS), pH7.2-7.4. It is preferred to solubilize the viral material with 0.1% NP40, a mild detergent, and to heat the solubilized viral material up to30 minutes at 50°-60° C., to elicit a slight unfolding of the outershell or envelope proteins which solubilized viral material is thendiluted with 1% SDS. The first injection contains an adjuvant; Freund'scomplete adjuvant (FCA) is preferred for this purpose. Of course, otheradjuvants known to those skilled in the art may also be used. The firstvaccination typically comprises a total volume of 2 ml, one ml of viralmaterial in buffer plus one ml of adjuvant. The viral material andadjuvant should be thoroughly mixed immediately prior to injection. In apreferred embodiment, the first vaccination contains 50-100 ug of viralmaterial in 1.0 ml of 1% SDS mixed with 1.0 ml of FCA.

Booster immunizations are generally prepared with adjuvant and typicallycontain 10-500 ug of viral proteins, preferably from about 50-100 ug perinjection in PBS, pH 7.2-7.4. It is preferred that booster immunizationsare prepared with Freund's incomplete adjuvant. It is further preferredthat the booster immunization contains 50-100 ug of viral materialsolubilized in 0.1% NP 40, heated for up to 30 minutes at 50°-60° C.,and diluted with 1% SDS. Booster injections begin from about 7 to 30days after the initial vaccination and every 7 to 30 days thereafteruntil the desired number of samples needed for the seroconversion panelis obtained. It is preferred that the first booster injection be giventwenty-four hours after the first vaccination. Preferably, up to fourbooster immunizations are given. It is further preferred that the fourthor final booster immunization be prepared with Freund's incompleteadjuvant and with viral lysate solubilized in 1% SDS and heated for upto 40 minutes at 65°-75° C. to elicit unfolding of the outer shell orenvelope proteins and to expose the interior or core proteins, therebyallowing an immunoresponse to these interior proteins.

A first blood sample is generally drawn and tested prior to the initialvaccination to establish a baseline antibody level. It is presentlypreferred to vaccinate by intracutaneous or subcutis injection, butother modes of administration, such as intramuscular injection may beused. The vaccination site is preferably the side of the neck, typicallyinjecting three to four different locations. Vaccination on the neck isconsidered to yield higher antibody titers, but other vaccination sitesas are known to those skilled in the art are suitable for raising thedesired immune antibody.

Blood is collected from the immunized animal by consecutive bleedingsafter the first immunization, preferably every 2 to 3 days, until asufficient number of consecutive blood samples, preferably 8 to 16 timepoints, are obtained for the desired seroconversion panel. The titer ofthe desired antibody of each blood sample or serum extracted therefromis measured. Once the timing and frequency of blood drawings (timepoints) is established for the particular immunogen being used, amultiple number of animals can be immunized. The animal is sacrificedand the blood collected at only one time point, each animal's time pointbeing different and including an animal for a baseline time point. Thetotal collected blood of one animal would represent one time pointsample. The advantage is that large amounts of antibody-containing bloodfor a particular time point in a seroconversion panel can be readilyobtained.

It is preferred to use serum from the immunized animal in aseroconversion panel. However, whole blood, plasma or any other form ofantibody as may be known to those skilled in the art may be used. Beforeuse, it is preferred to filter and sterilize the blood or serum and thenfreeze aliquots for later use; alternatively, the serum may befreeze-dried or dried or fractionated to enrich the IgG, IgM or IgAfractions.

The previously described method can be used to produce seroconversionpanels containing antibodies against several viruses including HIV-1,HIV-2, HTLV-1, HTLV-II, cytomegalovirus, Epstein-Barr virus, toxoplasma,and hepatitis B virus. It is also considered within the scope of theinvention to produce seroconversion panels containing antibodies againsta variety of other microorganisms such as Rubella, Borrelia b. (LYME),E. coli, salmonella, tetanus, streptococcus and Neisseria.

The previously described method can be used to produce antibodies forseroconversion panels in animals other than pigs, including rabbits,goats, mice, rats, sheep, cows, horses, and monkeys.

The following examples are considered illustrative of the presentinvention.

EXAMPLE 1 Porcine Immune IgG and IgM Against HTLV-1

An immunogen for injection was prepared with inactivated HTLV-1 lysate,containing proteins (p) 19, 24, 26, 38, and glycoprotein (gp) 46. TheHTLV-1 lysate, present in a concentration of 1 mg/ml in 0.1% NP 40 (anonionic detergent), 0.5 m NaCl and TNE buffer (29.2 g/l NaCL, 1.2 g/lTris, and 0.37 g/l EDTA), was heated for 30 minutes at 56° C. Onehundred ul of the HTLV-1 viral lysate were diluted with 900 ul of 1%SDS. Shortly before injection, this diluted viral lysate was mixed with1.0 ml Freund's comple adjuvant (FCA) to make the immunogen.

Just prior to injection, day 0, 20-50 ml of blood were drawn from theear vein of a four month old female Yorkshire mixed-breed pig and testedfor the presence of IgG and IgM antibodies to HTLV-1. This was thebaseline sample. The pig was then immunized by subcutis orintracutaneous injections at four different sites in the left side ofthe neck.

Booster injections contained 100 ul of HTLV-1 viral lysate in 900 ul of1% SDS mixed with 1 ml Freund's incomplete adjuvant (FIA). The firstbooster was administered twenty-four hours later (day 1), a secondbooster 16 days later (day 17), and a third booster 14 days later (day31). Seventeen days later (day 48), a fourth booster was prepared where100 ul of HTLV-1 viral lysate diluted in 900 ul 1% SDS was first heattreated for 40 minutes at a temperature from 65° to 70° C. and thenmixed with 1 ml FIA. The pig was vaccinated with this fourth booster onday 48. The pig received a total of five injections.

In addition to the baseline blood sample, 20 to 50 ml blood samples weredrawn from an ear vein on days 3, 5, 7, 9, 11, 13, 15, 17, 20, 23, 27,31, 38, 48 and 64. A total of sixteen samples of blood were drawn whenthe baseline is included.

Each blood sample, a positive control, and a negative control wasseparately tested for the presence of IgG antibodies to HTLV-1 and IgMantibodies to HTLV-1 using a Western Blot technique. The appearance andrelative strength of proteins bands were studied. Antibody titer foreach sample was determined using an ELISA assay. Serum was collectedfrom each of the sixteen blood samples, aliquotted in minute volumes of100-250 ul, labelled, and stored for use in seroconversion panelscontaining at least one aliquot from each of the sixteen samples.

EXAMPLE 2 Porcine Immune IgG and IgM Against HIV-1

The method of Example 1 was used except that inactivated HIV-1 virallysate was used instead of inactivated HTLV-1 viral lysate. The HIV-1lysate contained p18, p24, p31, gp41, gp48, p53, p56, p64, gp110, gp120,and gp160.

EXAMPLE 3 Sensitivity/Specificity Testing of Western Blot for IgGAgainst HTLV-1 Using Porcine HTLV-1 Seroconversion Panel

DuPont Western Blot strips precoated with HTLV-1 antigen (Lot #R0153H-91) were tested for sensitivity and specificity using a porcine HTLV-1seroconversion panel from Example 1. The aliquots of the seroconversionpanel were diluted 1 to 30 with PBS Tween. To a single Western Blotstrip, 2 ml of one of the diluted aliquots of serum, for example, day 1,was added and incubated for 30 minutes at room temperature on a rockingplatform. This step was simultaneously repeated for all of the dilutedaliquots of serum of the seroconversion panel and positive and negativecontrols. After incubation, the fluid was removed and each strip washedsequentially four times with 3 ml of PBS Tween.

Subsequently, 2 ml of a conjugate of goat anti-human IgG, gamma-chain,conjugated with alkaline phosphatase (Calbiochem, Lot #040090), diluted1 to 500 in PBS Tween was added to each strip and incubated for 30minutes at room temperature. The fluid was removed and each strip waswashed sequentially three times with 3 ml PBS Tween and then one timewith 3 ml 0.1M carbonate buffer (pH 9.2).

To each strip 2 ml of chromogen, 1:1 nitrobluetetrazolium salt (NBT) to5-bromo-4-chloro-3-indolylphosphate (BCIP) was added and incubated for10 minutes at room temperature. The reaction was stopped by adding 50 ulof 2N sulfuric acid. Each strip was then put in distilled water for fiveminutes, dried, and then the protein and glycoprotein bands were read.The strips are shown in FIG. 1.

On day 9, one protein band, p19, appeared. On day 23, four protein bandsappeared, p19, p24, p26, and p28, indicating a higher titer of IgG. Atday 38, 8 proteins and 1 glycoprotein appeared, p15, p19, p24, p26, p28,p32, p36, p53, and gp46, indicating a high titer of IgG, which remainedconstant through day 64.

EXAMPLE 4 Sensitivity/Specificity Testing of Western Blot for IgMAgainst HTLV-1 Using Porcine HTLV-1 Seroconversion Panel

The method of Example 3 was repeated except that the conjugate used was2 ml of goat anti-human IgM, mu-chain, conjugated with alkalinephosphatase (Calbiochem, Lot #041890) diluted 1:500 in PBS Tween. Theresulting strips are shown in FIG. 2.

In contrast with FIG. 1, FIG. 2 shows the presence of IgM by day 9 withthe appearance of three protein bands, p19, p26, and p28. At day 23, ahigh titer of IgM is indicated by the appearance of protein bands atp15, p19, p24, p26, p28, p32, and p36. This remains fairly constantuntil day 48 where, in contrast to the IgG seroconversion panel ofExample 3, the IgM titer declines as shown by the decreasing number ofprotein bands.

EXAMPLE 5 Sensitivity Testing Of ELISA Assay For IgG Against HTLV-1 InPorcine Seroconversion Panels

The sensitivity of the DuPont HTLV-1 ELISA test kit was tested bymeasuring the presence of IgG in the porcine seroconversion panel ofExample 1. Positive and negative controls were also measured. The ELISAassay was carried out in accordance with the manufacturer'sinstructions. The optical density (O.D.) readings are presented inFIG. 1. On day 9, a slight increase in the O.D. reading, 0.60, appearswhen compared to the negative control O.D. reading of 0.14. On day 23,there is a marked increase to 1.58, indicating a higher titer of IgG. Onday 38, there is another significant increase to 2.13, indicating a hightiter of IgG. From day 38 to day 64, the titer of IgG is fairlyconstant.

EXAMPLE 6 Sensitivity Testing Of ELISA Assay for IgM Against HTLV-1 InPorcine Seroconversion Panels

The sensitivity of the DuPont HTLV-1 ELISA test kit was tested bymeasuring the presence of IgM in the porcine seroconversion panel ofExample 1. Positive and negative controls were also measured. The ELISAassay was carried out in accordance with the manufacturer's instructionswith two modifications.

Prior to starting the ELISA assay, the seroconversion panel waspretreated to remove IgG, which interferes with the ELISA measurement ofIgM. Each aliquot of serum from the seroconversion panel was diluted1:10 in PBS Tween. The amount of IgG present in the sample was estimatedand an equivalent amount of Protein G (Pierce, Immuno Pure ImmobilizedProtein G) was mixed in with the diluted serum and incubated at 37° C.for 30 minutes. The diluted sample was then centrifuged for 5 minutes at10,000 rpm. The supernatant was removed and then used in the ELISAassay.

The second modification was the replacement of the IgG conjugate of thetest kit with an IgM conjugate, using goat anti-human IgM, mu-chain,conjugated with alkaline phosphatase (Calbiochem, Lot #041890) which wasdiluted 1:4000 in PBS Tween.

The resulting O.D. readings are presented in FIG. 2.

In contrast to Example 5, on day 9, on O.D. reading of 1.22 wasobtained, indicating a high titer of IgM. On day 23, the titer peaked,giving an O.D. reading of 1.75. On day 38, an O.D. reading of 1.17indicated the titer was decreasing. The titer continued to decrease asshown by the decreasing O.D. values.

These examples demonstrate the utility of porcine seroconversion panelsin testing the sensitivity and/or specificity of different assays whichdetect the presence or absence of antibodies to viral and/or othermicrobial infective agents.

While the preferred embodiments of the invention have been described, itwill be apparent to those of ordinary skill in the art that variouschanges and modifications may be made therein without departing from thespirit and scope of the invention. Accordingly, the above descriptionshould be construed as illustrative, and not in a limiting sense, of thescope of the invention being defined by the following claims.

We claim:
 1. A method for determining the sensitivity and/or specificityof an assay for detecting the presence or absence of human antibodieswhich bind to predetermined antigens of viruses or other microorganisms,comprising the steps of:(a) preparing a seroconversion panel of porcineimmune antibodies reactive to one or more predetermined antigens ofviruses or other microorganisms, said seroconversion panel comprising aplurality of time point antibody-containing blood samples sequentiallydrawn from a pig immunized with said antigens in which the reaction ofthe porcine antibodies to said antigens is similar to the reaction ofthe human antibodies to said antigens; (b) contacting an aliquot of asample of one or more predetermined antigens from an assay whosesensitivity and/or specificity is to be determined with the plurality ofporcine time point antibody-containing blood samples of theseroconversion panel for times and under conditions sufficient for thepredetermined antigens and porcine antibodies to form antigen-porcineantibody complexes; and (c) detecting the formation of anyantigen-porcine antibody complexes in step (b) by simultaneouslycontacting an anti-human antibody with any antigen-porcine antibodycomplex as formed, for times and under conditions sufficient for anyantigen-porcine antibody complexes formed in step (b) to react with theanti-human antibody.
 2. The method of claim 1, wherein theseroconversion panel comprises 8 to 16 sequential time pointantibody-containing blood samples drawn from a pig.
 3. The method ofclaim 1, wherein the porcine immune antibodies comprise IgG, IgM ormixtures thereof.
 4. The method of claim 1, wherein the porcine immuneantibodies comprise an antibody to a human retrovirus causing acquiredimmune deficiency syndrome or AIDS related complex (ARC).
 5. The methodof claim 4, wherein the porcine immune antibodies comprise IgG, IgM ormixtures thereof.
 6. The method of claim 1, wherein the porcine immuneantibodies comprise an antibody to HTLV-1.
 7. The method of claim 6,wherein the porcine immune antibodies comprise IgG, IgM or mixturesthereof.
 8. The method of claim 1, wherein the porcine immune antibodiesare antibodies to a human retrovirus causing acquired immune deficiencysyndrome or AIDS related complex (ARC) and to HTLV-1.
 9. The method ofclaim 8, wherein the porcine immune antibodies comprise IgG, IgM ormixtures thereof.
 10. The method of claim 1, wherein the porcine immuneantibodies comprise an antibody to cytomegalovirus (CMV).
 11. The methodof claim 10, wherein the porcine immune antibodies comprise IgG, IgM ormixtures thereof.
 12. The method of claim 1, wherein the porcine immuneantibodies comprise an antibody to Borrelia b. (LYME).
 13. The method ofclaim 12, wherein the porcine immune antibodies comprise IgG, IgM ormixtures thereof.
 14. The method of claim 1, wherein the porcine immuneantibodies comprise an antibody to Rubella.
 15. The method of claim 14,wherein the porcine immune antibodies comprise IgG, IgM or mixturesthereof.
 16. The method of claim 1, wherein the porcine immuneantibodies comprise an antibody to toxoplasma.
 17. The method of claim16, wherein the porcine immune antibodies comprise IgG, IgM or mixturesthereof.
 18. The method of claim 1, wherein the porcine immuneantibodies are selected from the group of antibodies to HIV-1, HIV-2,HTLV-1, HTLV-II, cytomegalovirus (CMV), and Epstein Barr virus.
 19. Themethod of claim 18, wherein the porcine immune antibodies comprise IgG,IgM or mixtures thereof.